1. Field of the Invention
This invention relates to a material gathering device for a mining machine and more particularly to a gathering platform having pivotal means extending laterally from the side portions of the gathering platform for gathering up the loose material deposited on the mine floor adjacent the mine wall.
2. Description of the Prior Art
Continuous mining machines, as illustrated in U.S. Pat. No. 3,774,969, are utilized in underground mining operations to continuously dislodge solid material from the face of a mine shaft. A boom member extends forwardly from an elongated body portion of the mining machine that is propelled through the mine on endless crawler tracks. The boom member is pivotally connected to the mining machine body portion and rotatably supports a cutter drum assembly having peripherally extending cutting elements. The cutter assembly extends transversely to the longitudinal axis of the body portion and upon rotation the cutting elements dislodges solid material from the mine face.
The cutter drum assembly is raised to a preselected vertical height in the mine as determined by the thickness of the coal seam. The cutter drum assembly is rotated and sumped into the mine face with the cutter drum assembly positioned adjacent the mine roof. Once the cutter drum assembly has advanced into the mine face, the boom member is pivoted downwardly to move the cutter drum assembly vertically downwardly through the face to make a shear cut in the face. The gathering device extends forwardly from the mining machine body portion and is positioned rearwardly of the cutter drum assembly. The dislodged material is gathered by the gathering device and fed rearwardly on the gathering device to an endless conveyor that extends the length of the mining machine. The conveyor transports the dislodged material to the rear of the mining machine where it is transferred to another suitable material hauling device such as a shuttle car or another endless conveyor for transporting the material out of the mine. By dislodging material from the mine face as the continuous mining machine advances forwardly in the mine, a mine passageway or room is formed. The mine walls or ribs extend rearwardly from the mine face. The walls are substantially parallel to one another spaced a distance apart determined by the cutting width of the cutter drum assembly. The gathering device includes a gathering platform having either gathering arms positioned on the platform oppositely of the receiving end of the conveyor or counterrotating gathering discs, similarly positioned for directing the dislodged material deposited rearwardly of the cutter drum assembly onto the gathering platform and therefrom onto the conveyor. Thus as the continuous mining machine forwardly advances to dislodge material from the mine face the rotating gathering arms or gathering discs direct the dislodged material to the receiving end of the conveyor as it is fed onto the gathering platform.
A problem is encountered in the gathering of loose material that is deposited on the mine floor adjacent the mine ribs or walls. Generally the width of the cutter drum assembly is greater than the width of the transverse front edge of the gathering platform so as to permit the mining machine to advance through the mine without the gathering platform contacting the mine ribs. Consequently, material dislodged from the mine face by the end portions of the cutter drum assembly adjacent the mine ribs is beyond the gathering limits of the gathering device.
U.S. Pat. No. 4,076,316 discloses a gathering device which is manuevered into a position abutting the mine rib to permit the gathering device side edge portion to pick up the loose material adjacent the rib. This is accomplished by laterally moving the cutter drum assembly relative to the mining machine so that one of the side edges of the gathering device is positioned in abutting relation with the mine rib.
As illustrated in U.S. Pat. No. 4,056,189 the gathering platform has a transverse front edge portion that tapers rearwardly toward the receiving end of the conveyor so as to provide for a continuous flow of dislodged material onto the gathering platform into the path of the gathering arms or discs. At the lateral ends of the forward transverse edge portion, plate members extend laterally and outwardly from the sides of the gathering platform. The plate members are fixed a preselected distance apart thereby forming the lateral limits of the gathering device. The vertical plates or sideboards are angled outwardly toward the mine ribs and serve to deflect the material at the side edges of the gathering platform onto the upper gathering surface of the platform into the path of the gathering devices on the platform. However, because the vertical sideboards are fixed at the side edges of the gathering platform material deposited on the mine floor beyond the gathering limits of the sideboards is not directed onto the gathering platform. Consequently, the uncollected dislodged material may become jammed between the sideboards and the mine ribs, requiring the dislodging operation to be interrupted to clear the jam.
U.S. Pat. No. 3,417,851 discloses a loading head for a mining machine that includes sideboards or wings that extend from each side of the forward transverse edge portion of the gathering platform. The wings are pivotally mounted on the gathering platform. Piston cylinder assemblies mounted on the gathering platform and connected to the wings are operable to pivot the wings to a preselected extended position relative to the gathering platform. In this manner the position of the wings can be adjusted relative to the width of the mine entry.
The wings include flat bottom plates which are movable over the gathering discs wherein the piston cylinder assemblies are operated to move the wings inwardly on the gathering platform. In this manner the wings may be moved to a preselected fixed position by control of the piston cylinder assemblies to provide for an expanded loading width or a restricted loading width.
While it has been suggested by the prior art devices to vary the width of the conveyor platform and to position a conveyor platform of a fixed width adjacent the mine rib for gathering up the loose material adjacent the mine rib, none of the known devices provide a gathering platform having side edges which are maintained closely adjacent or in contact with the mine ribs without becoming jammed or damaged if the side edges should encounter an obstruction at the mine ribs. The known devices do not permit the gathering platform to by pass an obstruction at the mine ribs without incurring damage to the side edges.
Therefore, there is need to provide a gathering device for a continuous mining machine in which the side edge portions are maintained in a position relative to the mine wall to direct the loose material on the mine floor at the mine wall onto the gathering platform as the mining machine advances through the mine. The side edge portions must be freely pivotal on the gathering platform to prevent the side edge portions from becoming jammed against the mine walls and damaged.